The $5 billion credit union in Marlborough, Mass., said the deal with SunPower Corp., in San Jose, Calif., allows homeowners who join DCU to receive a loan of up to $50,000 for a high-efficiency solar power system.

The loans, which will be originated from DCU, can be shared with other credit unions that will work directly with their respective members who are homeowners.

Available for terms up to 20 years, DCU said borrowers may also be eligible for the 30% federal tax credit that is available for the installation of solar power systems.